Closes: swh/infra/sysadm-environment#5496

related to T1330

related to T1242

change cherry picked from python module template
commit 71b117ba0cf9f1251b1cac26d0994df03a4c787d

Example of such repository for swh isswh-lister-github.

Implementation is ugly but it works.

Downstream expects id as integer, so try to cast those.
If successful, then it's an id indeed.
Otherwise, let it flow, it's possibly either a callsign or a
phid (both string).

Also remove arcanist as a runtime dependency

It's not working entirely yet (example of error
https://forge.softwareheritage.org/P132).

Apparently, posting nested object in post form is not possible -
https://github.com/kennethreitz/requests/issues/2885.

With the previous code, the query was actually wrong but it returned
all the repositories anyway.

This has the unfortunate side-effect to let the dry_run flag being
ignored...
Thus resulting in being False by default.